Disclosure of Invention
In order to solve the technical problem that the sensitivity of the existing GPC3 detection kit is not high, the invention provides a kit for improving the GPC3 detection sensitivity, which has higher GPC3 detection sensitivity and wider linear range.
The invention also provides a preparation method of the kit for improving the detection sensitivity of GPC 3.
The invention is realized by the following technical scheme:
the kit for improving the detection sensitivity of GPC3 comprises a reagent M and a reagent R, wherein the reagent M is prepared by coupling a mouse anti-human GPC3 monoclonal antibody with magnetic bead particles and diluting the magnetic bead particles, and the diameter of the magnetic bead particles is 0.8-3 mu M;
the magnetic bead particle is coupled with a mouse anti-human GPC3 monoclonal antibody and diluted by a magnetic bead particle coupled antibody diluent to prepare a reagent M, and the components of the magnetic bead particle coupled antibody diluent comprise: proclin300, buffers, surfactants and proteins;
the reagent R is prepared by labeling rabbit anti-human GPC3 polyclonal antibody with alkaline phosphatase and diluting with alkaline phosphatase labeled antibody diluent.
Further, in the reagent M, the mass ratio of the magnetic bead particles to the mouse anti-human GPC3 monoclonal antibody is 0.3:0.2-0.5;
in the reagent R, the mass ratio of alkaline phosphatase to rabbit anti-human GPC3 polyclonal antibody is (0.25-0.5) to (0.5-1);
the mass ratio of the magnetic bead particles to alkaline phosphatase is 0.3:0.25-0.5.
Further, the concentration of each component of the magnetic bead particle coupled antibody diluent is as follows:
proclin 300:0.03-0.1%, buffer solution: 0.02-0.05 mol/L, surfactant: 0.2% -2%, protein: 0.1 to 0.5 percent and the pH value is 7.0 to 8.0;
the buffer solution comprises any one of PB buffer solution, MOPS buffer solution, TES buffer solution, HEPES buffer solution and DIPSO buffer solution; the surfactant comprises any one of Brij-35, S9, emulgenA90 and PEG-6000; the protein is BSA or bovine gamma globulin.
Further, in the reagent M, the diameter of the magnetic bead particles is 3 μm;
the mass ratio of the magnetic bead particles to the mouse anti-human GPC3 monoclonal antibody to the alkaline phosphatase to the rabbit anti-human GPC3 polyclonal antibody is 0.3:0.5:0.5:0.5;
the components of the magnetic bead particle coupled antibody diluent comprise 0.05% Proclin300, 0.02mol/L DIPSO buffer solution, 2% PEG-b000 and 0.1% bovine gamma globulin, and the pH=7.4;
the alkaline phosphatase-labeled antibody diluent comprises the following components: 0.9% sodium chloride, 1mM magnesium chloride hexahydrate, 0.1mM anhydrous zinc chloride, 0.1% bovine serum albumin, 0.05% Proclin300, 0.02M Tris-HCl buffer pH 7.4.
A method for preparing a kit for improving the detection sensitivity of GPC3, comprising:
activating magnetic bead particles with diameters of 0.8-3 mu m by using an activating agent;
adding the activated magnetic bead particles into a mouse anti-human GPC3 monoclonal antibody for coupling reaction;
adding glycine solution quenching liquid to react after the coupling reaction is completed, and washing and resuspending after the reaction is completed to obtain the magnetic bead particle coupling antibody;
taking alkaline phosphatase, rabbit anti-human GPC3 polyclonal antibody and glutaraldehyde for crosslinking reaction;
and after the crosslinking reaction is finished, adding ethanolamine for reaction, and dialyzing after the reaction is finished to obtain the alkaline phosphatase labeled antibody.
Further, the magnetic bead particles are repeatedly washed by PBS buffer solution before activation, and the activation process comprises the following steps: and (3) re-suspending the washed magnetic bead particles by adopting PBS buffer solution, adding an activating agent EDC for reaction for 30min, and separating and discarding supernatant after the activation is finished.
Further, the coupling reaction is as follows: the activated magnetic bead particles were added with a murine anti-human GPC3 monoclonal antibody and coupled at room temperature.
Further, the concentration of the glycine solution quenching liquid is 1mol/L, and the pH=8.0.
Further, the crosslinking reaction is as follows: dissolving alkaline phosphatase and rabbit anti-human GPC3 polyclonal antibody in normal saline, adding 1% glutaraldehyde, reacting at room temperature 120rmp for 15min, and then reacting in dark for 4h.
Further, the concentration of the ethanolamine is 1mol/L, the ethanolamine is added and then reacted for 2 hours at room temperature and 120rmp, after the reaction is finished, the mixed solution is dialyzed in PBS buffer solution at 4 ℃ overnight, and the mixed solution is preserved at-20 ℃ by glycerol which contains 1% BSA and has the same volume as the dialyzed mixture.
One or more technical solutions in the embodiments of the present invention at least have the following technical effects or advantages:
the invention provides a kit for improving GPC3 detection sensitivity, which can remarkably improve GPC3 detection sensitivity and expand GPC3 detection linear range by adjusting magnetic bead particle diameter, alkaline phosphatase and antibody dosage and improving dilution of magnetic bead particle coupling antibody, wherein GPC3 detection limit can reach 10pg/mL, detection range can reach 36-19860pg/mL, and precision CV is less than 5%.
Detailed Description
The advantages and various effects of the present invention will be more clearly apparent from the following detailed description and examples. It will be understood by those skilled in the art that these specific embodiments and examples are intended to illustrate the invention, not to limit the invention.
Throughout the specification, unless specifically indicated otherwise, the terms used herein should be understood as meaning as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification will control.
Unless otherwise specifically indicated, the various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or may be prepared by existing methods.
The technical scheme provided by the embodiment of the invention aims to solve the technical problems, and the overall thought is as follows:
according to the invention, the GPC3 detection sensitivity is improved and the GPC3 detection linear range is enlarged by adjusting the diameter of the magnetic bead particles, the alkaline phosphatase and the dosage of the antibody and optimizing the diluent of the magnetic bead particles coupled with the antibody.
The invention optimizes the lowest detection limit of the kit by adjusting the diameter of the magnetic bead particles, and the magnetic bead particles with smaller diameters provide larger antibody binding area under the same mass concentration, thereby being beneficial to widening the linear range of immunoassay. The larger diameter of the magnetic bead particles will improve the performance of the reaction system for detecting the low concentration sample, and the lowest detection limit can be optimized, but the increase of the diameter can bring about the decrease of the total surface area of the solid phase carrier, so that the amount of the antibody bound on the carrier is reduced, thereby influencing the upper detection limit.
Glutaraldehyde crosslinking labelling method uses bifunctional crosslinking agent as bridge to combine enzyme and antibody. The most commonly used cross-linking agent is glutaraldehyde. It has two active aldehyde groups which can be bound to amino groups on the enzyme molecule and the antibody molecule, respectively. The glutaraldehyde method is divided into a one-step method and a two-step method according to the method of adding the reagent, and the one-step method is adopted in the invention, so that the operation is simple and convenient.
After the GPC3 in the sample is incubated with the magnetic bead particles coated with the anti-GPC 3 monoclonal antibody and the anti-GPC 3 polyclonal antibody-alkaline phosphatase label, the GPC3 is combined with the magnetic bead particles coated with the anti-GPC 3 monoclonal antibody, and the other site of the GPC3 is combined with the anti-GPC 3 polyclonal antibody-alkaline phosphatase label to form a complex. After the reaction is completed, the magnetic field adsorbs the magnetic bead particles, and unbound substances are washed. The added luminescent substrate is decomposed by alkaline phosphatase, phosphate group is hydrolyzed to remove a phosphate group, an unstable intermediate is generated, the intermediate is decomposed into adamantanone with a molecule and a methyl m-oxybenzoate anion with a molecule in an excited state through intramolecular electron transfer, chemiluminescence is generated when the intermediate returns to a ground state, the photon number in the reaction is measured through a photomultiplier, and the generated photon number is proportional to the concentration of GPC3 in a sample. From the calibration curve, the content of GPC3 in the sample can be calculated.
In particular, the invention
The kit for improving the detection sensitivity of GPC3 comprises a reagent M and a reagent R, wherein the reagent M is prepared by coupling a mouse anti-human GPC3 monoclonal antibody with magnetic bead particles and diluting the magnetic bead particles, and the diameter of the magnetic bead particles is 0.8-3 mu M;
the magnetic bead particle is coupled with a mouse anti-human GPC3 monoclonal antibody and diluted by a magnetic bead particle coupled antibody diluent to prepare a reagent M, and the components of the magnetic bead particle coupled antibody diluent comprise: proclin300, buffers, surfactants and proteins;
the reagent R is prepared by labeling rabbit anti-human GPC3 polyclonal antibody with alkaline phosphatase and diluting with alkaline phosphatase labeled antibody diluent.
Further, in the reagent M, the mass ratio of the magnetic bead particles to the mouse anti-human GPC3 monoclonal antibody is 0.3:0.2-0.5;
in the reagent R, the mass ratio of alkaline phosphatase to rabbit anti-human GPC3 polyclonal antibody is (0.25-0.5) to (0.5-1);
the mass ratio of the magnetic bead particles to alkaline phosphatase is 0.3:0.25-0.5.
Further, the concentration of each component of the magnetic bead particle coupled antibody diluent is as follows:
proclin300:0.03 to 0.1 percent of buffer solution: 0.02-0.05 mol/L, surfactant: 0.2% -2%, protein: 0.1 to 0.5 percent and the pH value is 7.0 to 8.0;
the buffer solution comprises any one of PB buffer solution, MOPS buffer solution, TES buffer solution, HEPES buffer solution and DIPSO buffer solution; the surfactant comprises any one of Brij-35, S9, emulgenA90 and PEG-6000; the protein is BSA or bovine gamma globulin.
In the magnetic bead particle coupled antibody diluent:
MOPSO belongs to Good's buffer solution, its Chinese name is 3- (N-morpholino) -2-hydroxy propane sulfonic acid, new zwitterionic buffer solution for biological research, its buffer capacity is in pH 6.2-7.6, it is one of the most commonly used buffers in low-temperature biochemical work; TES Chinese name is N-tris (hydroxymethyl) methyl-2-aminoethanesulfonic acid, and the buffer capacity of the buffer system is within the range of pH 6.8-8.2; HEPES Chinese name 4-hydroxyethyl piperazine ethane sulfonic acid is a hydrogen ion buffer, and the buffer capacity of the buffer system is in the range of pH 6.8-8.2; the DIPSO Chinese name is 3- [ N, N-di (hydroxyethyl) amino ] -2-hydroxy propane sulfonic acid, and the buffering capacity of the buffer system is in the range of pH 7.0-8.2; these several buffer systems can be controlled constantly over a range around pH7.4 for a longer period of time.
The polyethylene glycol series products can be used as ester type surfactant, and PEG-6000 belongs to polyethylene glycol with relatively low molecular weight, and can be used as solvent, cosolvent and stabilizer; polyoxyethylene lauryl ether, also called Brij35, is a nonionic surfactant used as a dispersing agent, and effectively separates hydrophilic proteins and hydrophobic proteins through membrane permeation without changing the biological activity of the hydrophilic proteins and the hydrophobic proteins; surfactant S9 (Tetronic 1307) is an excellent defoamer and dispersant that reduces the matrix effect of blood samples; the polyoxyethylene biphenyl styrenated phenyl ether is also called EmulgenA90, and is a nonionic surfactant and a low-foaming surfactant.
Protein substances such as BSA and bovine gamma globulin which are irrelevant to antigen-antibody reaction can play a role in blocking, reduce nonspecific adsorption and reduce a 0 point signal value, thereby increasing the signal-to-noise ratio and improving the sensitivity.
A kit for improving the detection sensitivity of GPC3 of the present application will be described in detail with reference to examples, comparative examples and experimental data.
Examples
The present application sets 14 examples and 4 comparative examples.
1. Preparation of reagents
1.1 preparation of reagent M:
the antibody in the magnetic bead particle coupled antibody is a mouse anti-human GPC3 monoclonal antibody, the diameter of the magnetic bead particle is 0.8-3 mu m, 100 mu L of 3mg/mL magnetic bead particle is taken to be placed in a 2mL EP tube, and the EP tube is placed on a magnetic separator for 4min, and the supernatant is discarded; adding 150 μl of 0.1M PBS buffer solution, blowing uniformly, separating on a magnetic separator for 4min, discarding supernatant, and repeatedly washing for 3 times;
after washing, 90. Mu.L of 0.1mol/L PBS buffer solution is added for resuspension; adding 100 mu L of 10mg/mL EDC activator, blowing uniformly, placing on an oscillator, reacting for 30min, placing on a magnetic separator, separating for 4min, and discarding supernatant;
then adding 20-500 ug of mouse anti-human GPC3 monoclonal antibody for coupling, specifically adopting 500ug of mouse anti-human GPC3 monoclonal antibody in experiments, diluting with 0.1mol/L PBS buffer solution to a total volume of 500 ul, shaking overnight at room temperature, placing on a magnetic separator for separation for 4min, discarding supernatant, and washing with the PBS buffer solution for 2 times;
adding 1mol/L glycine solution quenching liquid with pH of 8.0, uniformly mixing for 30min at room temperature, adding 0.01M PBS buffer solution containing 0.1% Tween 20 and 0.1% BSA, washing for 2 times, magnetically separating supernatant, washing with 0.1% BSA PBS buffer solution, re-suspending to 1mL, and standing at 2-8 ℃ for later use. The diluted magnetic bead particle coupled antibody solution can be directly used as a reagent M after being diluted by 50 times.
1.2 preparation of reagent R:
0.25-0.5 mg alkaline phosphatase and 0.5-1 mg rabbit anti-human GPC3 polyclonal antibody are respectively taken and dissolved in 0.5mL physiological saline, 0.05mL of 1% glutaraldehyde is added, the mixture is reacted for 15min at room temperature of 120rmp and then is reacted for 4h in a dark place, 0.1mL of 1M ethanolamine is added and reacted for 2h at room temperature of 120rmp, the mixed solution is dialyzed overnight in PBS buffer at 4 ℃, and the mixture containing 1% BSA and the same volume of glycerin as the dialyzed mixture is stored at-20 ℃. The alkaline phosphatase-labeled antibody can be directly used as a reagent R after being diluted 1000 times.
2. Performance test of comparison reagent
The sensitivity of the Human Glypican3 detection kit (Quantikine ELISA) of R & D was tested by using the kit as an alignment kit.
The analytical sensitivity, also known as the limit of detection (limit of detection), is based on zero concentration and is used to distinguish between no-to-no analytical capability. The invention evaluates the capability of detecting the low concentration sample by the ratio of the signal value of the low concentration sample and the signal value of the 0 point (expressed by signal to noise ratio), wherein the larger the signal to noise ratio is, the more the sample can be distinguished from the 0 point, and the lower the detection limit is.
2.1 alignment of the kit was tested using different concentrations of calibrator and the results are shown in table 1:
table 1 results of alignment of the kit to the calibrator
| Concentration of calibrator (pg/mL) | 0D value of calibrator |
| 0 | 0.110 |
| 78.1 | 0.135 |
| 156 | 0.194 |
| 313 | 0.266 |
| 625 | 0.421 |
| 1250 | 0.812 |
| 2500 | 1.501 |
| 5000 | 2.498 |
| r | 0.9931 |
Conclusion: alignment kit for measuring linear correlation coefficient r= 0.9931 of calibrator (detection range 78.1-5000 pg/mL)
2.2 alignment kit height the linearity of the low value mixed samples.
The high value samples are diluted in proportion to samples of different concentrations with the low value samples (the low value samples are near the lower limit of the linear interval). And (3) respectively measuring the samples by using a comparison kit, measuring each diluted concentration for 3 times, respectively calculating the average value of the 0D value detection results of each diluted concentration, and calculating the average value of the sample concentration according to a calibration curve.
TABLE 2 comparative reagent test sample results
Conclusion: according to the analysis sensitivity of 20.6pg/mL and the actual test result, the comparison kit can not detect samples less than or equal to 20pg/mL, and samples exceeding 5000p/mL need to be diluted for detection.
3. Examples and comparative examples settings and sensitivity test thereof
Examples 1-14 and comparative examples 1-4 were prepared by the above reagent preparation method, and specific components or preparation materials of the kit are shown in tables 3 and 4.
The prepared kit is subjected to sensitivity test, and is optimized by adopting a chemiluminescence method, and the reaction parameters are as follows: 50. Mu.L of reagent M, 50. Mu.L of reagent R, 50. Mu.L of serum sample (which was assayed for concentration by ELISA kit for R & D), incubation at 37℃for 20min, washing of the magnetic separation followed by reading, results are given in tables 3, 5:
3.1 optimizing the magnetic bead particle diameter and the alkaline phosphatase to antibody ratio to improve sensitivity
TABLE 3 chemiluminescent process optimization labeling process results
In Table 3, the components of the magnetic bead microparticle-coupled antibody dilutions of comparative example 1 and examples 1, 2 and 4 were the same as in example 3.
Conclusion: as shown in table 3, comparative example 1 uses a magnetic bead particle diameter (0.8 μm), a 72/0 signal to noise ratio of 3.15, a 4965/2489 signal to noise ratio of 1.97, and a linear correlation coefficient r=0.9980; in example 1, compared with comparative example 1, the photon value of the sample is measured to be increased by using the diameter (1.5 μm) of the magnetic bead particles, the signal to noise ratio of 72/0 is 3.55, the signal to noise ratio of 4965/2489 is 1.96, and the linear correlation coefficient r=0.9987; example 2 using a magnetic bead particle diameter (3 μm), the photon value of the measured sample was increased, the 72/0 signal to noise ratio was 3.89, the 4965/2489 signal to noise ratio was 2.00, and the linear correlation coefficient r=0.9982, indicating that magnetic bead particles with a diameter of 1.5 to 3 μm could further improve the detection sensitivity of GPC 3;
compared with example 2, the dosage of alkaline phosphatase in example 3 is increased from 0.25mg to 0.5mg, the 72/0 signal to noise ratio is 4.34,4965/2489 signal to noise ratio is 2.04, and the linear correlation coefficient r= 0.9996 shows that the detection sensitivity of GPC3 can be improved by increasing the dosage of alkaline phosphatase; compared with example 2, example 4 increased the alkaline phosphoric acid dosage to 0.5mg, increased the antibody dosage to 1mg, and measured the photon value of the sample to be increased, the 72/0 signal-to-noise ratio was 4.09,4965/2489 signal-to-noise ratio was 2.01, and the linear correlation coefficient r= 0.9992; however, example 4 continued to increase antibody usage to 1mg compared to example 3, but the 0 point signal value increased and the signal to noise ratio and linearity did not increase further, indicating that too high an antibody concentration would have an adverse effect. In optimizing the labeling process, the conditions of example 3 were optimal.
3.2 optimizing the magnetic bead microparticle coupled antibody Diluent to improve sensitivity
TABLE 4 optimized magnetic bead microparticle coupled antibody dilutions
In Table 4, the diameters of the magnetic bead particles of examples 5 to 14 and comparative examples 2 to 4 were the same as those of example 3.
TABLE 5 magnetic bead microparticle coupled antibody diluent optimization test results
Conclusion: as shown in Table 5, the photon value, signal-to-noise ratio and linearity of example 3 (pH 7.4) were all higher than those of comparative example 2 (pH 6.5) and comparative example 3 (pH 8.5), indicating that the diluent was suitable around pH 7.4; the photon value, signal to noise ratio and linearity of example 3 (0.1% BSA added) were all higher than control 4 (no BSA added); compared with example 3 (PB buffer system), example 5 (MOPS buffer system), example 6 (TES buffer system), example 7 (HEPES buffer system), example 8 (DIPSO buffer system) all reduced the 0 point signal value, further improving the signal to noise ratio, with example 8 (DIPSO) performing best; example 9 (with 2% peg-6000 added), example 10 (with 2% brij-35 added), example 11 (with 0.2% s9 added), example 12 (with 0.2% emulgena90 added) reduced the 0 point signal value and increased the signal value at other concentrations, thus increasing the signal to noise ratio, with example 9 (with 2% peg-6000 added) performing best, compared to example 3 (without surfactant added); example 13 (0.1% bovine gamma globulin addition) also reduced the 0 point signal value and increased the signal value at other concentrations compared to example 3 (0.1% bsa addition), thereby increasing the signal to noise ratio; example 14, with DIPSO buffer system, 2% PEG-6000 was added and 0.1% bovine gamma globulin was added for better overall effect.
4. Example 14 comparison with an alignment kit
The two detection kits were evaluated from detection range and linearity, blank limit, detection limit, analytical sensitivity, and precision.
4.1 detection Range and linearity
The sample concentrations of 10-19860pg/mL were detected simultaneously in the example 14 and the R & D kit, and the sample concentrations detected with the comparison reagent were the theoretical concentrations calculated from the dilution ratio at concentrations exceeding the detection range of the comparison reagent (36-4965 pg/mL).
TABLE 6 comparison of example 14 with the alignment reagent
| Sample concentration pg/mL | R&D kit measured 0D value | Example 14 measurement of photon values |
| 0 | 0.115 | 3256 |
| 10 | / | 4256 |
| 20 | 0.113 | 7156 |
| 36 | 0.116 | 13156 |
| 72 | 0.149 | 26123 |
| 162 | 0.202 | 46411 |
| 360 | 0.288 | 119654 |
| 635 | 0.431 | 211563 |
| 1246 | 0.81 | 401236 |
| 2489 | 1.457 | 798456 |
| 4965 | 2.396 | 1612354 |
| 9930 | 3.265 | 3256471 |
| 19860 | 3.468 | 6598731 |
| 10/0 signal to noise ratio | / | 1.31 |
| 36/0 signal to noise ratio | 1.01 | 4.04 |
| 4965/2489 signal to noise ratio | 1.64 | 2.02 |
| 19860/9930 signal to noise ratio | 1.06 | 2.03 |
| (36-4965)r | 0.9918 | 0.9999 |
| (36-19860)r | 0.8049 | 0.9999 |
Conclusion: as shown in Table 6, example 14, using a magnetic bead particle diameter (3 μm), the alkaline phosphatase to antibody ratio was 0.5mg:0.5mg of magnetic bead microparticle conjugated antibody dilution contains 2% PEG-6000, 0.1% bovine gamma globulin, 0.05% Proclin300, pH7.4 in 0.02mol/L DIPSO buffer. The reaction parameters are as follows: 50. Mu.L of reagent M, 50. Mu.L of reagent R, 50. Mu.L of serum sample, incubated at 37℃for 20min, washed and read after magnetic separation. Example 14 measured a higher signal-to-noise ratio and linear correlation coefficient than the R & D reagent, and a wider sample detection range than the R & D kit.
4.2 blank Limit
The zero concentration calibrator is used as a sample for detection, the measurement is repeated for 20 times, the OD value or the RLU value (relative luminescence value) of 20 measurement results is obtained, and the average value is calculatedStandard Deviation (SD) and LOB value +.>Performing two-point regression fitting according to the OD value or RLU value result between the zero concentration calibration material and the adjacent concentration calibration material to obtain a primary equationI.e. the LOB value is brought into the above equation, and the corresponding concentration value is calculated, i.e. the blank space.
TABLE 7 blank test results
| Number of measurements | OD value determination by contrast reagent | EXAMPLE 14 determination of RLU value |
| 1 | 0.111 | 3256 |
| 2 | 0.112 | 3321 |
| 3 | 0.109 | 3150 |
| 4 | 0.114 | 3210 |
| 5 | 0.108 | 3012 |
| 6 | 0.111 | 3412 |
| 7 | 0.109 | 3214 |
| 8 | 0.104 | 2108 |
| 9 | 0.102 | 3510 |
| 10 | 0.113 | 3245 |
| 11 | 0.104 | 3175 |
| 12 | 0.106 | 3026 |
| 13 | 0.105 | 2964 |
| 14 | 0.104 | 3126 |
| 15 | 0.117 | 3071 |
| 16 | 0.113 | 3148 |
| 17 | 0.113 | 3254 |
| 18 | 0.115 | 3164 |
| 19 | 0.112 | 3058 |
| 20 | 0.109 | 3192 |
| Average value of | 0.110 | 3131 |
| Standard deviation of | 0.004 | 274 |
| LOB value | 0.118 | 3680 |
| Blank limit | 11.90 | 1.54 |
Conclusion: the alignment reagent blank was 11.90pg/mL and the example 14 blank was 1.54pg/mL. The blank of example 14 was lower than the alignment reagent.
4.3 detection Limit
The detection is performed on 5 low value samples with approximate detection Limit (LOD) of concentration, each sample is detected 5 times, and the number of detection results below the value of the blank Limit (LOB) is less than or equal to 3.
Table 8 detection limit test results
Conclusion: example 14 has a detection limit lower than that of the comparison reagent and has higher sensitivity.
4.4 repeatability
Human serum samples of 3 different concentrations were assayed, each of which was repeated 10 times, and the average value and standard deviation of the 10 assay results were calculated to calculate the Coefficient of Variation (CV).
Conclusion: the CV of the comparison reagent is less than 10%, and the CV of the example 14 is less than 5%.
4.6 conclusion
The invention adopts a chemiluminescent detection method, optimizes the labeling process and the magnetic bead particle coupled antibody diluent, and improves the detection sensitivity and the detection range. The magnetic bead particles with proper diameters and proper amount of alkaline phosphatase and antibody can be used for obviously improving the test photon value and the signal-to-noise ratio, thereby improving the detection sensitivity.
The performance of the example using the chemiluminescent method was superior to ELISA, with example 14 being optimal, using a magnetic bead particle diameter (3 μm), alkaline phosphatase to antibody ratio of 0.5mg:0.5mg of magnetic bead microparticle conjugated antibody dilution contains 2% PEG-6000, 0.1% bovine gamma globulin, 0.05% Proclin300, pH7.4,0.02M DIPSO buffer. The reaction parameters are as follows: 50 mu L of reagent M, 50 mu L of reagent R and 50 mu L of serum sample are incubated for 20min at 37 ℃, and after washing and magnetic separation, the measured signal to noise ratio and linear correlation coefficient are higher than those of the R & D ELISA reagent, the detection range of the sample is wider than that of the R & D kit, the detection limit is lower, and the CV is better. The detection limit is 10pg/mL, the detection range is 36-19860pg/mL, and the precision CV is less than 5%.
Finally, it is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.